Bug 5109: Handle stand alone leaf nodes in CDS streaming

Bug 5109: Handle stand alone leaf nodes in CDS streaming

Modified AbstractNormalizedNodeDataOutput to output the leaf set QName
that is now passed to leafSetEntryNode if no parent LeafSetNode QName is
present. Modified NormalizedNodeInputStreamReader accordingly.

I also found that OrderedLeafSetNode was not handled correctly.
AbstractNormalizedNodeDataOutput#startOrderedLeafSet needs to set
lastLeafSetQName.

The NormalizedNodePruner assumed a leaf set entry node must have a
parent and threw an exception if not, similarly with leaf node and anyXML
node. But all 3 can be standalone so I modified NormalizedNodePruner to
handle it.

Change-Id: I02a71d9280dac0eb466ff401699a40d3d8826220
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>